theorem tsallisHessian_uniform_on_perp (_hJ : 0 < J) (q : ℝ) (hq : 0 < q)
(v : Fin J → ℝ) (_hv : orthToOne J v) :
-- The Hessian quadratic form at uniform is proportional to ‖v‖²
-- with coefficient -q · J^{q-1}
tsallisHessianDiag J q * vecNormSq J v ≤ 0 := by
apply mul_nonpos_of_nonpos_of_nonneg
· simp only [tsallisHessianDiag]
apply mul_nonpos_of_nonpos_of_nonneg (by linarith)
exact rpow_nonneg (Nat.cast_nonneg J) _
· simp only [vecNormSq]
exact Finset.sum_nonneg fun j _ => sq_nonneg _Appendix Lemmas 1-3 (Paper 2, Appendix A)